Method for producing glucose isomerase

Abstract

Production of glucose isomerase from facultative aerobic microorganisms by limiting oxygen supply to growth-limiting amounts in the presence of excess glucose and other nutrients in sufficient amounts. Enzyme yield from oxygen growth-limiting proportions is superior to yields obtained from glucose growth-limiting circumstances.

What is claimed is: 
     
       1. Process for production of a glucose isomerase product by fermentation, which process comprises the fermentation of a facultative aerobic, glucose isomerase producing microorganism with a supply of oxygen which is growth-limiting, and with a source of carbon and energy which represses glucose isomerase synthesis yet is readily converted anaerobically to non repressing degradation products added in slight excess and all other nutrients are added in sufficient amounts, and thereafter recovering the glucose isomerase product. 
     
     
       2. Process for production of a glucose isomerase product according to claim 1, wherein a glucose isomerase strain of Bacillus coagulans is used as the glucose isomerase producing microorganism. 
     
     
       3. Process for production of a glucose isomerase product according to claim 2, wherein the Bacillus coagulans is an atypical strain characterized by growth on only inorganic sources of nitrogen and by an ability to grow at 65° C. 
     
     
       4. Process for production of a glucose isomerase product according to claim 1 wherein the fermentation medium has therein from 1-20% excess glucose as the source of carbon and energy. 
     
     
       5. Process for production of a glucose isomerase product according to claim 1 wherein the process is carried out as a continuous fermentation. 
     
     
       6. Process for production of a glucose isomerase product according to claim 5, wherein the carbon and energy source is added separately from other nutrients. 
     
     
       7. Process for production of a glucose isomerase product according to claim 5, wherein the dilution rate has a value between 0.05 and 0.20. 
     
     
       8. Process for production of a glucose isomerase product according to claim 1, wherein the glucose isomerase is produced by means of a dosed batch fermentation and wherein the carbon and energy source is added separately from the other nutrients. 
     
     
       9. Process for production of a glucose isomerase product according to claim 1, wherein glucose, hydrolyzed starch or xylose is used as the carbon and energy source.